In one or more embodiments, the second user profile includes access rights authorizing access to information about an available data storage capacity in the memory of the storage device. This case advantageously allows a second-profile user to know whether there is any available space in the memory of the storage device before considering writing data therein, which facilitates management of the memory space of the device by all users, preventing for example the situation where a second-profile user who, depending on the embodiment, may or may not have read access to the memory of the device, including in a “drop zone” of the memory, and begins to write data in the memory of the device when the available space is insufficient for writing the data.

In one or more embodiments, wherein the access rights included in the second user profile only authorize the writing of data in the memory of the data storage device. The access rights of second-profile users are then advantageously limited to only the writing of data, which maximizes security for first-profile users during use of the device by second-profile users, as well as the confidentiality of data stored in the memory of the storage device. For example, the storage device may be a secure storage medium (USB key, SD card, removable disk, etc.) that only authorizes one “owner” profile for the person who can read, edit, and delete files that are stored therein, and forcing a “guest” or “write-only” mode for everyone else who can only place files there.